Discovery of Rapamycin Rapamycin is a macrocyclic triene antibiotic that binds to the cytosolic protein FK-binding protein 12 (FKBP12) and inhibits mTOR pathway by directly binding to the mTOR Complex 1 (mTORC1). It is a potent immunosuppressant having a variety of uses both in vitro and in vivo and is used to prevent organ rejection after transplantation. Chemical structure of...